US patent application published US 2013/0236944 A1 relates to methods for inactivating antibiotics in the environment by means of using enzyme, such as laccase, lipase, cellulase, ketoreductase, β-lactamase and/or erythromycin-esterase. The compositions disclosed have as purpose to decontaminate the polluted environments and to prevent the environment pollution by antibiotics from waste and wastewater effluents before they reach the environment. The laccase of the disclosure is from Trametes versicolor (or Coriolus versicolor). The lipase of the disclosure is from Achromobacter spp. The cellulose of the disclosure is from Trichodrema reesei. The antibiotics targeted by the laccase of the disclosure are selected from the cyclines family (tetracycline, oxytetracycline (OTC) and chlortetracycline) or the β-lactams family, whose penicillin (amoxicillin), cephalosporin (cefdinir) and/or carbapenem (imipenem). The antibiotics targeted by the lipase of the disclosure are selected from the macrolide family (erythromycin) or the β-lactam family (amoxicillin). The antibiotics targeted by the ketoreductase of the disclosure are selected from the β-lactam family (amoxicillin or imipenem). The antibiotics targeted by the β-lactamase are selected from the β-lactam family (penicillins, cephalosporins, cephamycins or carbapenems). The antibiotics targeted by the erythromycin-esterase of the disclosure are selected from the macrolides family (erythromycin or clarithromycin). The disclosure further provides a solid support comprising at least one antibiotic-inactivating enzyme immobilized thereon. The solid supports can include adsorbent materials. The solid supports can be a membrane to which the enzymes are immobilized by covalent linkage. The enzymes can also be immobilized by gel entrapment. The solid support can be packed in a column or used in packed-bed reactors with environmental or waste waters to be treated flowing through the reactor and being in contact with immobilized enzymes. The solid support can also be coupled to other solid supports to enhance the inactivation process.
The advantages of using solid supports are well known. The contact area between the antibiotics to be treated and the enzyme is increased, favoring therefore the rate and the yield of the enzymatic reaction. Furthermore, solid supports are known to be relatively resistant to high pressure and to high temperature.
However, the setting of the above disclosure, namely the packing in a column or the use in the packed-bed reactors would cause difficulties such as back mixing with “plugs” of fluid passing through the reactors, leading to various issues, such as difficulties to get even distribution of the load (i.e. the water to be treated) on the whole carrier surface.